Senecio actinella Greene (redirected from: Packera actinella)
Family: Asteraceae
[Packera actinella (Greene) W.A. Weber & A. Löve,  more...]
Senecio actinella image

Perennials, (7-)20-30(-40+) cm (rhizomes exfoliating). Herbage densely lanate-tomentose, glabrescent (especially on adaxial faces of leaves). Stems single. Leaves mostly basal; petiolate; blades narrowly obovate, (2-)3-7(-10) × 1-2(-3+) cm, bases tapered, margins subentire to denticulate (cauline leaves bractlike). Heads 1(-3). Calyculi of (1-)5-8+ linear to filiform bractlets (lengths 1 / 3 - 3 / 4 phyllaries). Phyllaries ± 21, 8-12 mm, tips greenish (with white bristles). Ray florets ± 13; corolla laminae usually 8-10 mm (sometimes tubular, unexpanded, heads then perhaps technically disciform). Cypselae hairy.

Flowering summer. In duff, rocky woodlands, especially in pine-dominated areas; 2000-3000 m; Ariz., N.Mex.; Mexico (Chihuahua, Durango).

Plants of Senecio actinella with relatively small proximal leaves similar to basal leaves and adaxial leaf faces early glabrate have been recognized as var. mogollonicus; the distinction is difficult to maintain. Receptacles in Senecio actinella are sometimes insect-infested.

General: Perennial, 7-40 cm tall; stems solitary; herbage densely woolly-tomentose to nearly glabrous; rhizomatous.

Leaves: Mostly basal, alternate, narrowly obovate or oblanceolate, 2-10 cm long, 1-3 mm wide, cauline blades few, bract-like, greatly reduced, thick, leathery, densely woolly pubescent to nearly glabrous, especially above, margins nearly entire to denticulate; blades petiolate.

Flowers: Heads in loose corymb- to panicle-like arrays; involucre obconic, 5-7 mm long, 3-6 mm wide; phyllaries 7-10 or more, in 1-2 series, greenish to purple, puberulent, gland-dotted, the margins and apex membranous; disk flowers only, mostly 15-30, 1-2 mm long, yellowish; flowers August-September.

Fruits: Achene, cylindric, ribbed, pubescent; pappus of 30-80 white to straw-colored bristles.

Ecology: Coniferous forests, rocky woodlands; 1700-2900 m (5500- 9500 ft); Apache, Cochise, Coconino, and Graham counties; New Mexico, Arizona, northern Mexico.

Notes: Senecio actinella may be propagated by seed or by division.

Editor: Springer et al. 2008